This November eos.org reported a new theory describing how Earth’s abundant water probably came to be. New clues for a second source of Earth’s water came from studying possible sources of the hydrogen in Earth’s water. The early theory was that asteroids provided all of Earth’s water since the “…deuterium to hydrogen ratio is close to that
found in asteroids.”
However, water found deep within Earth, between the core and mantle, was recently found to have less deuterium than most of Earth’s water, hence it may not have come from asteroids. Also found deep in Earth’s mantle were helium and neon, probably also “…inherited from the solar nebula,” the material slowly becoming our current sun.
In those early years, within the solar nebula, “’…waterlogged asteroids” collided and grew into planetary embryos. One of these became the planet Earth. Hydrogen from the solar nebula contributed to Earth’s early atmosphere. Then “isotopic fractionation” pulled the hydrogen toward the center, where iron attracted it to Earth’s core, while heavier deuterium
remained in the magma which cooled, becoming the mantle.
It is now thought that most of Earth’s water was from asteroids, but some came from the solar nebula as described. We can make a reasonable guess that life has an easier, a much easier, time evolving when water is readily available–as it was on Earth billions of years ago when deep sea vents apparently provided safe enough havens for the first capable molecules to get together to thrive and reproduce.
Most likely, most exoplanets were formed in ways similar to Earth’s formation, i.e. from parts of solar nebulas that gradually cooled and congealed into planets and eventually orbited their parent sun. It would be fascinating to study a young sun that still had a nebula we could envision or deconstruct.
Author of The Archives of Varok
The View Beyond Earth (Book 1.)
The Webs of Varok (Book 2.)
Nautilus Silver Award 2013 YA
ForeWord IBPA finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest (Book 4. Released Nov.21, 2016)
Excerpts, Synopses, Reviews, On Writing, Characters and More-
Reviews of significant books- http://www.goodreads.com/Cary_Neeper
How the Hen House Turns- http://www.ladailypost.com
Complexity, Bio, Bibliography and Links- http://caryneeper.com
Astrobiology- https://astronaut.com search:Who’s Out There